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Problem 7.A company is interviewing potential employees. Suppose that each candi

ID: 3050394 • Letter: P

Question

Problem 7.A company is interviewing potential employees. Suppose that each candidate is either qualified, or unqualified with given probabilities q and 1- q, re- spectively. The company tries to determine a candidate's qualifications by asking 20 true-false questions. A qualified candidate has probability p of answering a question correctly, while an unqualified candidate has a probability p of answering incorrectly. The answers to different questions are assumed to be independent. If the company con- siders anyone with at least 15 correct answers qualified, and everyone else unqualified, give a formula for the probability that the 20 questions will correctly identify someone to be qualified or unqualified.

Explanation / Answer

Here, we can use the binomial distribution and formula to be used would be as under: -

n!/x!(n-x)!*p^x*q^n-x

Where n would be the number of questions i.e. 20, x would be the number of questions to be answered correctly i.e. 15, 16, 17, 18, 19 and 20. p would be the probability of answering the question correctly/incorrectly and q would be 1-p.